Leslie Richard Groves Biography and Timeline

Manhattan Project

Groves appoints Oppenheimer to head the project's secret weapons laboratory

Manhattan Engineering District

Colonel Leslie Groves is assigned command of the Manhattan Engineering District

Manhattan Project

Colonel Leslie Groves is assigned command of the Manhattan Engineering District

Belgian Congo Uranium Purchase

Groves purchases about 1,250 tons of high-grade Belgian Congo uranium ore stored on Staten Island.

Promotion to Brigadier General

Groves is promoted to brigadier general shortly after taking command of the Manhattan Engineer District.

Manhattan Project

Groves purchases 52,000 acres (210 km) of land in Tennessee for "Site X", which will become the Oak Ridge, Tennessee laboratory and production site

Site X

Groves purchases 52,000 acres (210 km) of land in Tennessee for "Site X", which will become the Oak Ridge, Tennessee laboratory and production site

Manhattan Project

The Manhattan Project is given permission to use the highest wartime priority rating by the War Production Board

War Production Board

The Manhattan Project is given permission to use the highest wartime priority rating by the War Production Board

Met Lab Engineering Deadline

During a visit to the Metallurgical Laboratory, Groves orders long-delayed engineering decisions for plutonium production to be settled within five days.

Manhattan Project

Leslie Richard Groves appoints Robert Oppenheimer to coordinate the scientific research of the project at the "Site Y" laboratory

Site Y

Leslie Richard Groves appoints Robert Oppenheimer to coordinate the scientific research of the project at the "Site Y" laboratory

DuPont Plutonium Assignment

Groves places DuPont in charge of engineering and construction for the plutonium-production project.

Industrial Scale Production Decision

The Military Policy Committee decides to bypass pilot stages for major production methods and proceed directly toward industrial-scale plants.

Manhattan Project

Groves appoints Oppenheimer to head the project's secret weapons laboratory. From 1942-1946 under the control of the US Army Corps of Engineers, under the administration of General Leslie R. Groves

Manhattan Project

From 1942-1946 under the control of the US Army Corps of Engineers, under the administration of General Leslie R. Groves

Role range: 1939-1945

Y-12 Completion Deadline

Groves presses for the first Y-12 electromagnetic racetrack to be completed by July as detailed plant plans are reviewed.

Oak Ridge Reservation Closed

Fencing of the Oak Ridge reservation is completed and the secret production site is closed to normal public access.

Y-12 Racetrack Rebuild

After repeated failures to operate the first Alpha racetrack reliably, Y-12 is shut down for major equipment rebuilding.

K-25 Barrier Redesign

Groves orders a change in the gaseous-diffusion barrier approach after continuing failures to produce a suitable barrier for K-25.

Jumbo Test Vessel Authorised

Groves and Oppenheimer decide to plan a full-scale fission-bomb test, and Groves authorises construction of the massive steel vessel called Jumbo.

S-50 Construction Contract

Groves orders rapid construction of the S-50 thermal-diffusion plant at Oak Ridge on an exceptionally compressed schedule.

Hanford D Reactor Criticality

Hanford's D Reactor reaches criticality with sufficient excess reactivity to overcome fission-product poisoning.

Atomic Target Selections to Marshall

Groves forwards the Manhattan Project target group's recommendations to General George C. Marshall.

Atomic Attack Directive Drafted

Groves drafts the directive authorising atomic attacks when bomb availability and weather permit, listing Hiroshima, Kokura, Niigata and Nagasaki.

Manhattan Engineer District Abolished

The Manhattan Engineer District is formally abolished, ending the Army organisation that built the first atomic bombs.